3.19 Antituberculars
Mycobacterium tuberculosis is the causative agent of tuberculosis (TB), a disease that primarily impacts the lungs but can infect other parts of the body as well. It has been estimated that one third of the world’s population has been infected with M. tuberculosis, and millions of new infections occur each year. Treatment of M. tuberculosis is challenging and requires clients to take a combination of drugs for an extended time. Complicating treatment even further is the development and spread of multidrug-resistant strains of this pathogen.[1]
Mechanism of Action: Antituberculars work by impacting the synthesis or transcription of mycobacteria RNA or inhibiting the synthesis of mycolic acids in the cellular wall. Mycobacteria can develop resistance to antitubercular medications; therefore, strict compliance to drug regimen must be emphasized.
Indications: Antitubercular medications are selective for mycobacteria and work by inhibiting growth or selectively destroying mycobacteria.[2]
Nursing Considerations: Antitubercular medications require at least six months of treatment. Many antitubercular medications may impact liver function, and liver enzymes should be monitored carefully. Other side effects to medication administration include GI symptoms, peripheral neuropathy, and vision changes.[3]
Side Effects/Adverse Effects: Common side effects of antitubercular medications include GI upset. Adverse effects include hepatotoxicity. Antitubercular medications can also decrease the effectiveness of oral contraceptives, so alternative contraceptive methods should be used.
Health Teaching & Health Promotion: Advise clients that medications must be taken as directed. It is important that clients understand the significance of continuing drug therapy even after symptoms have resolved to prevent the spread of disease and antibiotic resistance to TB. Drug therapy may be continued for six months to two years. If a client notices any change in visual acuity or eye discomfort, it should be reported immediately to the health care provider. Clients should also be advised to avoid alcohol during antitubercular therapy because of the increased risk of liver toxicity. Foods containing tyramine, such as tuna and Swiss cheese, should be avoided.[4]
Now let’s take a closer look at the medication grid on isoniazid in Table 3.19a and rifampin in Table 3.19b.[5]
Table 3.19a Isoniazid Medication Grid
| Class/Subclass | Prototype/Generic | Nursing Considerations | Therapeutic Effects | Side/Adverse Effects |
|---|---|---|---|---|
| Antitubercular (also known as antimycobacterials) | isoniazid | Direct observed therapy (DOT) may be initiated to ensure compliance with long-term therapeutic regimen
Multiple-drug resistant tuberculosis (i.e., resistance to at least isoniazid and rifampin) presents difficult treatment problems. Treatment must be individualized and based on susceptibility studies May decrease effectiveness of oral contraceptives. Clients sho